* Global growth worries return after stimulus rally * Gold falls from 6-1/2-month top, copper slips too * Palladium slides by nearly 5 percent * Soybeans at lowest since mid-August (Adds quotes, details; updates prices) By Eric Onstad and Manolo Serapio Jr LONDON/SINGAPORE, Sept 24 (Reuters) - Oil, gold and copper fell on Monday as the dollar firmed and investors worried that stimulus measures by central banks would take time to lift sluggish global growth and boost demand for raw materials. Oil dropped more than a dollar and copper and gold pulled further away from multi-month highs touched last week in the wake of a broad rally after global central banks unleashed easing programmes to boost growth. Palladium slid nearly 5 percent and Chicago soybeans hit their weakest since mid-August, pressured by rising output and slower demand. Moves by the United States, Europe and Japan to buy bonds to bolster their economies had lifted commodity prices in recent weeks, but investors struggled to push prices even higher against the backdrop of a slowdown in China and the euro zone and an uneven U.S. economic recovery. "Slowing economic growth is the major concern for oil markets," said Olivier Jakob, energy consultant at Petromatrix in Zug, Switzerland. "I think the market is taking a dose of reality here so investors are pulling back a little. It's a little overheated across the board," said Mark Pervan, global head of commodity research at ANZ in Australia. Adding to the sour sentiment was a drop in Germany's business sentiment in September for a fifth straight month to its lowest since early 2010, raising fears of recession. "September's fall in the German Ifo business survey is a reminder that even the euro-zone's strongest economies are suffering from a serious economic downturn," said Jennifer McKeown, economist at Capital Economics. A firmer dollar added to the pressure on commodities priced in the greenback by making them more expensive for holders of other currencies. OIL Brent crude fell below $110 a barrel, dropping $2 to a low of $109.42 before recovering slightly to trade around $110.14 by 1201 GMT, a loss of 1.3 percent. U.S. crude shed 1.7 percent to an intraday low of $91.34 per barrel. Brent dropped 4.5 percent last week, while U.S. crude lost 6.2 percent in their biggest weekly losses since June amid demand worries and as top oil exporter Saudi Arabia vowed to boost output to bring prices down. Daniel Jaeggi, co-founder of Swiss-based commodities house Mercuria Energy Trading, said on Monday that oil prices still reflected "the Iranian risk premium", but suggested that lower demand should put pressure on the market. "Overall, I think Brent around $100 (per barrel) - somewhere around $95 and $100 - given the macro-economic circumstances we have, is a lot more reasonable than $120." GOLD, COPPER DOWN Spot gold dropped 1.0 percent to a low of $1,755.30 an ounce, after rising to as high as $1,787.20 on Friday, its loftiest level in 6-1/2 months. Gold has gained about 10 percent over the last five weeks, its biggest such rise since September 2011, as investors braced for higher inflation following moves by global central banks to boost liquidity. But bullion has found it difficult to clear $1,800, a level last seen in November last year. "Part of the issue is the lack of obvious catalysts in the near term to take gold prices higher," Deutsche Bank analyst Daniel Brebner said. "There are a number of low growth concerns which could underpin the dollar, and keep gold somewhat moribund near term." Palladium, mainly used in auto catalyst systems to curb pollution, tumbled nearly 5 percent to a session low, and was on track for its biggest one-day fall since March 6. Besides the renewed risk aversion, some of the premium attached to platinum group metals by labour unrest in South Africa has dissipated recently. The sell-off in commodities hit base metals markets, where copper hit a one-week low of $8,157.75 per tonne, down 1.5 percent, slipping further from a 4-1/2-month top of $8,422 touched last Wednesday. Copper was also weighed by weak demand from top consumer China ahead of a week-long national holiday, and as Chinese manufacturers were still waiting to see orders from Beijing's infrastructure expansion plans. In agricultural markets, private estimates of higher U.S. production and slowing demand from top consumer China dragged Chicago soybeans and corn lower. Wheat edged down after the last session's gains as growing economic concerns weighed on prices of commodities, also including oil and metals. Chicago soybeans fell nearly 2 percent, to below $16 a bushel for the first time since mid-August. Analytics firm Informa Economics raised estimates for U.S. soybean and corn production while farmers in South America also geared up for a large crop. In softs, arabica coffee and cocoa futures eased, but sugar futures were steady, supported by rain delaying the tail end of Brazil's harvest. (Additional reporting by Christopher Johnson, Jan Harvey, Maytaal Angel; Editing by Alison Birrane)

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